Semiconductor Contact Formation via Ion Beam Etching and Thermal Reaction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for forming contacts on semiconductor substrates result in large distances between the gate stack structure and contacts, leading to material wastage, increased device size, and higher on-resistance, which complicates manufacturing and usage.
Innovation Solution
A method involving ion beam etching and heating to form quasi-self-aligned contacts with reduced distance to the gate stack structure, using metals like nickel, titanium, or tungsten, and an insulating layer to prevent unwanted reactions, allowing for a smaller contact size and reduced etching requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to form contacts with large distance from gate stack structure, then etching allowance and adjustment margins are sufficient, but device size increases, material consumption increases, and on-resistance increases
Solution Approach 1:
The patent applies preliminary structuring of the contact opening through lithography and etching before metal deposition, creating a pre-defined contact region that guides subsequent self-aligned metal formation. This preliminary action establishes precise geometric constraints that enable reduced spacing while maintaining manufacturing tolerances
Solution Approach 2:
The contact structure utilizes self-aligned formation where the metal automatically conforms to the pre-structured opening geometry during deposition and heating processes. The contact opening structure serves its own alignment function, eliminating the need for additional alignment margins and enabling reduced device size
2Area of stationary object
If contact distance to gate stack structure is reduced, then device size decreases and material is saved, but manufacturing precision requirements increase and control becomes more difficult
Solution Approach 1:
The contact opening is pre-structured with precise dimensions and positioning before metal deposition. This preliminary structuring establishes strict geometric boundaries that guide metal formation, enabling reduced contact spacing while maintaining alignment precision through the pre-defined opening structure
Solution Approach 2:
The pre-structured contact opening acts as a self-aligning template that automatically positions the contact metal with high precision. The opening geometry itself provides the alignment reference, eliminating the need for external alignment margins and enabling compact device design with controlled precision
3Loss of substance
If contact size is reduced to save material and decrease device size, then on-resistance decreases, but etching control becomes more critical and manufacturing difficulty increases
Solution Approach 1:
The contact opening is etched with precise dimensions before metal deposition, creating a pre-defined template that guides subsequent material formation. This preliminary etching action establishes the final contact footprint with controlled material removal, enabling reduced contact size while maintaining etching control through pre-planned geometry
Solution Approach 2:
The etched contact opening structure serves as a self-limiting template that automatically controls the final contact dimensions. The opening geometry provides inherent etching control by defining the boundaries of material removal, enabling reduced contact size with controlled etching through the self-defined geometric constraints
4Productivity
If distance between contact and gate stack structure is reduced, then cell concentration increases and on-resistance decreases, but the risk of unwanted metal reactions with substrate increases
Solution Approach 1:
An insulating layer is deposited over the substrate and contact regions before metal deposition. This preliminary insulation action creates a protective barrier that prevents unwanted metal-substrate reactions, enabling reduced contact spacing while maintaining reliability through pre-established chemical isolation
Solution Approach 2:
The insulating layer acts as an intermediary barrier between the contact metal and the semiconductor substrate. This intermediate layer prevents direct contact and unwanted chemical reactions between metal and substrate, enabling compact device design with improved reliability through chemical isolation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the production of semiconductor devices with significantly reduced contact size, lower material costs, improved transportation, and higher cell density, while reducing on-resistance and eliminating the need for precise etching allowances.
Implementation Method 1
By carrying out at least one ion beam etching step between the application of the at least one metal and the heating of the semiconductor substrate in an etching direction which is inclined to an axis oriented perpendicularly to the outside of the semiconductor substrate
Implementation Method 2
the semiconductor substrate with the at least one metal applied to the at least one partial area and the at least one edge region is heated... the at least one metal and the at least one semiconductor material react to form a semiconductor-metal material
Data Source
Figure 1a~1b
Figure 2
Figure 3~4
AI summary
The invention relates to a method for forming a contact on a semiconductor substrate (50) comprising the steps of applying at least one metal (66) to at least one exposed partial area (68) of an outer side of the semiconductor substrate (50) and/or a layer applied to the semiconductor substrate (50), wherein the partial area (68) is surrounded by at least one edge region (70) of an insulating layer (58), and wherein the at least one edge region (70) of the insulating layer (58) is at least partly covered with the at least one metal (66), heating the semiconductor substrate (50), as a result of which the at least one metal (66) applied to the at least one partial area (68) reacts with at least one semiconductor material of the at least one partial area (68) to form a semiconductor-metal material as final material or further processing material of the at least one contact, and performing an etching step using an etching material having a higher etching rate for the at least one metal (66) than for the semiconductor-metal material. Furthermore, the invention relates to a semiconductor device.